In recent years, tactile sense presentation devices have been proposed which each feed back a sense of touch by transmitting vibrations when a user touches a key on a touch panel keyboard, and makes the user feel that the user has “pushed” a key.
For example, Patent Literature 1 discloses a structure which holds both ends of a piezoelectric bimorph element made of piezoelectric ceramics or the like by using low elastic bodies, and connects a vibration member to a center of the piezoelectric bimorph element. The structure according to Patent Literature 1 transmits vibrations to a user via the connected vibration member by inputting an alternating-current signal to the piezoelectric bimorph element to cause vibrations.
PTL 1: Japanese Patent Application Laid-Open No. 2005-303937